Antimicrobial coating forming kink resistant feature on a vascular access device

ABSTRACT

A vascular access device includes an antimicrobial coating that provides kink resistance to a catheter. The antimicrobial coating can extend along a length of the catheter to provide antimicrobial protection when the catheter is inserted into the patient&#39;s vasculature. The antimicrobial coating can also increase the effective diameter of the catheter to minimize the likelihood that the catheter will become kinked.

BACKGROUND OF THE INVENTION

The present invention relates generally to vascular access devices thatinclude an antimicrobial coating. In particular, the present inventionis directed to an antimicrobial coating that forms a kink resistantfeature on a vascular access device.

It is becoming more common for vascular access devices such as cathetersto include an antimicrobial coating to minimize the occurrence ofinfections caused by the use of the vascular access device. For example,catheters oftentimes include an antimicrobial lubricant that provideslubrication during insertion of the catheter into the patient'svasculature and then provides antimicrobial protection while thecatheter is inserted.

One problem that exists with the use of current antimicrobial coatingsis the risk of toxicity caused when excess antimicrobial agents enterthe bloodstream or are distributed to a confined location. In order toobtain antimicrobial protection for a substantial duration of time (e.g.for the entire time that the catheter is inserted), a significant amountof antimicrobial lubrication must be present on the catheter. With theuse of significant amounts of lubrication, there is a risk that too highof a concentration of antimicrobial agents will be distributed.

Another problem that exists with the use of catheters is kinking. Forexample, when a peripheral intravenous catheter is inserted into thepatient's vasculature, it will typically be bent at the point where thecatheter exits the catheter adapter (e.g. due to catheter adapter beingplaced flat on the patient's skin) and possibly where the catheterenters through the patient's skin or vasculature. This bending canoftentimes result in kinks that limit or prevent fluid flow through thecatheter.

BRIEF SUMMARY OF THE INVENTION

The present invention extends to vascular access devices that include anantimicrobial coating that provides kink resistance to a catheter. Theantimicrobial coating can extend along a length of the catheter toprovide antimicrobial protection when the catheter is inserted into thepatient's vasculature. The antimicrobial coating can also increase theeffective diameter of the catheter to minimize the likelihood that thecatheter will become kinked.

In one embodiment, the present invention is implemented as a vascularaccess device. The vascular access device includes a catheter adapter, acatheter that extends distally from the catheter adapter, and anantimicrobial coating. The antimicrobial coating is applied to at leasta portion of the catheter adapter and comprises a base material thatreleases one or more antimicrobial agents when the antimicrobial coatingis inserted within a patient's skin. The base material also provideskink resistance to the catheter.

In some embodiments, the antimicrobial coating can be positionedadjacent the catheter adapter and/or can include an increased diameterportion. In some embodiments, the increased diameter portion ispositioned adjacent the catheter adapter.

In some embodiments, the length of the antimicrobial coating can beconfigured so that the distal end of the antimicrobial coating ispositioned near an intimal layer of a vein when the catheter is insertedinto the vein. In some embodiments, this length can be between 7 mm and12 mm.

In some embodiments, the base material can be hydroscopic to enhance therelease of the antimicrobial agents when the antimicrobial coating ispositioned within the patient's skin. In some embodiments, the basematerial can be a UV cured acrylate-urethane or a heat-curedpolyurethane. In some embodiments, the base material may have a hardnessthat slightly exceeds a hardness of the catheter.

In some embodiments, the vascular access device can also include anantimicrobial lubricant that is applied to the catheter. In someembodiments, the antimicrobial lubricant can be applied to a portion ofthe catheter that does not include the antimicrobial coating.

In another embodiment, the present invention is implemented as avascular access device. The vascular access device includes a catheteradapter, a catheter that extends distally from the catheter adapter, andan antimicrobial coating. The antimicrobial coating extends from thecatheter adapter towards a distal end of the catheter and has anincreased diameter portion adjacent the catheter adapter.

In another embodiment, the present invention is implemented as acatheter that comprises an antimicrobial coating applied to a portion ofthe catheter. The antimicrobial coating has a proximal end and a distalend. The proximal end comprises an increased diameter portion. Theantimicrobial coating also comprises a base material that releases oneor more antimicrobial agents when the antimicrobial coating ispositioned within a patient's skin.

This summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key features oressential features of the claimed subject matter.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be obvious from thedescription, or may be learned by the practice of the invention. Thefeatures and advantages of the invention may be realized and obtained bymeans of the instruments and combinations particularly pointed out inthe appended claims. These and other features of the present inventionwill become more fully apparent from the following description andappended claims, or may be learned by the practice of the invention asset forth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which the above-recited and otheradvantages and features of the invention can be obtained, a moreparticular description of the invention briefly described above will berendered by reference to specific embodiments thereof which areillustrated in the appended drawings. Understanding that these drawingsdepict only typical embodiments of the invention and are not thereforeto be considered to be limiting of its scope, the invention will bedescribed and explained with additional specificity and detail throughthe use of the accompanying drawings in which:

FIG. 1 is a perspective view of a vascular access device that includesan antimicrobial coating that functions as a kink resistant feature onthe catheter.

FIG. 1A is a perspective view of the vascular access device of FIG. 1showing the antimicrobial coating along a length of the catheter.

FIG. 2 illustrates a cross-sectional view of a portion of a vascularaccess device.

FIG. 3 illustrates a cross-sectional view of the vascular access deviceof FIG. 2 when it has been inserted into the vasculature of a patient.

FIG. 3A is a detailed cross-sectional view of the antimicrobial coatingin contact with dermal layers of the skin, the primary source ofresident bacteria.

FIG. 4 is a cross-sectional view of a vascular access device with theaddition of an antimicrobial lubricant on a distal portion of thecatheter.

FIG. 5 is a cross-sectional view of a vascular access device when theantimicrobial coating extends along a full length of the catheter.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates an example vascular access device 100 that includesan antimicrobial coating 103 in accordance with one or more embodimentsof the invention. Vascular access device 100 includes a catheter adapter102 and a catheter 101 that extends distally from the catheter adapter.Although vascular access device 100 is shown as including extensiontubing, a vascular access device in accordance with the presentinvention need not include extension tubing. Further, vascular accessdevice 100 is an example of a peripheral intravenous catheter. However,an antimicrobial coating in accordance with the present invention can beapplied on other types of catheters including central venous cathetersand peripherally inserted central catheters. In short, any device thatincludes a flexible component that is inserted into the vasculature of apatient can include an antimicrobial coating on the component inaccordance with one or more embodiments of the present invention.

The antimicrobial coating may comprise any material that hasanti-pathogenic properties which may be applied to the surface of acatheter and that has sufficient rigidity to minimize the likelihoodthat the catheter will become kinked when it is bent. For example, insome embodiments, the antimicrobial coating can comprise a base materialmatrix and one or more antimicrobial agents. In some embodiments, thebase material matrix can be a UV curable, hydrophilic material thatcontains an antimicrobial agent with controlled release (elution)characteristics. Alternatively, a base material can be coated with anantimicrobial coating from which an antimicrobial agent will elute whensubject to a fluid.

For example, the base material, in some embodiments, can be a watersoftening UV cure matrix such as UV cured acrylate-urethanes, orheat-cured polyurethanes. Water softening materials can be preferred inmany implementations over non-softening materials as such materialsbecome more flexible when inserted into the patient and exposed tofluid. Catheters are oftentimes formed of such water softeningmaterials. Therefore, using an antimicrobial coating that also consistsof a water softening material can match the properties of the coating tothe catheter to minimize any negative impact the coating may have on theperformance of the catheter and on patient comfort. For example, in someembodiments, the hardness of the antimicrobial coating may only slightlyexceed that of the catheter. This increased hardness minimizes thelikelihood that the catheter will become kinked while minimallyaffecting the patient's comfort during catheter use because the catheterremains substantially elastic.

Examples of materials that could be used to form the antimicrobialcoating of the present invention includes those disclosed in U.S. Pat.No.: 8,512,294 titled Vascular Access Device Antimicrobial Materials AndSolutions; U.S. patent application Ser. No.: 12/397,760 titledAntimicrobial Compositions; U.S. patent application Ser. No.: 12/476,997titled Antimicrobial Coating Compositions; U.S. patent application Ser.No.: 12/490,235 titled Systems And Methods For Applying An AntimicrobialCoating To A Medical Device; and U.S. patent application Ser. No.:12/831,880 titled Antimicrobial Coating For Dermally Invasive Devices.Each of these patent documents is incorporated herein by reference.

In one particular embodiment, the antimicrobial agent used to form theantimicrobial coating can be chlorhexidine including chlorhexidinediacetate (CHA) and/or chlorhexidine gluconate (CHG). However, any otherantimicrobial agent that will elute from a base material or from acoating on a base material could be used.

FIG. 1A illustrates a detailed view of catheter 101 and antimicrobialcoating 103. As shown, antimicrobial coating 103 can extend fromcatheter adapter 102 along a portion of catheter 101. In this example,antimicrobial coating 103 extends along about half the length ofcatheter 101. However, in some embodiments, antimicrobial coating 103can extend along a larger or smaller length of catheter 101, includingextending to the distal tip.

As best seen in FIG. 1A, the proximal end of antimicrobial coating 103can have a diameter that increases towards catheter adapter 102.Catheter 101 is most likely to kink as it exits from catheter adapter102. Therefore, increasing the diameter of antimicrobial coating 103towards catheter adapter 102 provides additional kink resistance wherekinks would otherwise be most likely to occur. In some embodiments, suchas is shown in FIG. 1A, the increase in the diameter of antimicrobialcoating 103 can be gradually increased to the point that theantimicrobial coating has the same diameter as the nose of catheteradapter 102.

Although in FIGS. 1 and 1A antimicrobial coating 103 is shown asextending only up to catheter adapter 102, in some embodiments, theantimicrobial coating can extend proximally onto a portion of thecatheter adapter. Also, in some embodiments, the diameter of theantimicrobial coating at the point where it meets the catheter adaptercan be configured to be less than the diameter of the catheter adapterat that point. Further, in some embodiments, rather than having agradually increasing diameter, the diameter may step up from a smallerdiameter to a larger diameter at some distance from the catheteradapter. Accordingly, the present invention encompasses many differenttypes of increases in the diameter of the antimicrobial coating as thecoating approaches the catheter adapter.

FIG. 1A also shows that the diameter of antimicrobial coating 103decreases to a minimal amount at the distal end of the coating. Having aminimal diameter at the distal end of the coating can minimize anydiscomfort caused to the patient when catheter 101 is inserted.

FIG. 1A also illustrates that, in some embodiments, an antimicrobiallube 104 can be applied to any portion of the catheter that does notinclude the antimicrobial coating. However, the present inventionencompasses embodiments where only an antimicrobial coating is appliedto a catheter regardless of whether the antimicrobial coating extendsonly along a portion of the length of the catheter.

FIG. 2 provides a cross-sectional view of vascular access device 100 tobetter illustrate the increase in the diameter of antimicrobial coating103. As shown, towards a distal end of antimicrobial coating 103, thediameter of the coating is minimal. In some embodiments, the diameter atthis distal end may be between 10 and 100 microns. Then, asantimicrobial coating 103 approaches catheter adapter 102, the diametergradually increases to form an increased diameter portion 103 a.Increased diameter portion 103 a can provide increased kink resistanceto the catheter as it exits catheter adapter 102. For example, becauseof the increased diameter of portion 103 a, the catheter will beunlikely to bend sufficiently at the point that it exits catheteradapter 102 to cause a kink. In other words, increased diameter portion103 a will tend to cause catheter 101 to bend more gradually as it exitscatheter adapter 102 rather than bending sharply at the exit point.Similarly, the other (smaller diameter) portions of antimicrobialcoating 103 can provide additional rigidity to catheter 101 to minimizethe likelihood of any sharp bends that may result in kinks.

FIG. 3 illustrates how antimicrobial coating 103 can provide kinkresistance to catheter 101. As shown, catheter adapter 102 is positionedgenerally flat on the patient's skin 300. Because of this, catheter 101will be angled downward from the point where it exits catheter adapter102 to the point where it enters through the patient's skin 300.Antimicrobial coating 103, and more particularly, increased diameterportion 103 a causes catheter 101 to bend more gradually between theinsertion point and catheter adapter 102 thereby minimizing thelikelihood of kinking.

FIG. 3 also illustrates an example where the length of antimicrobialcoating 103 is configured so that the coating extends through the dermallayers of skin 300 and into the entrance to vein 301. In this way,antimicrobial agents can be released from antimicrobial coating 103directly to the dermal layers and at the insertion points into skin 300and into vein 301. These locations, and particularly the dermal layers,are the primary source of bacteria that may enter vein 301. For thisreason, the length of antimicrobial coating 103 can be configured toensure that antimicrobial agents are targeted to these locations.

FIG. 3A provides a detailed view of a portion of FIG. 3 to illustratethe dermal layers 302 of skin 300 where catheter 101 is inserted. Asshown, antimicrobial coating 103 has a sufficient length to ensure thatthe coating is in contact with the dermal layers. By employing anantimicrobial coating that elutes antimicrobial agents (e.g. a coatingthat is hydroscopic), the antimicrobial agents can be distributed to thedermal layers (and surrounding areas) in a controlled manner to minimizethe possibility of toxicity from the agents.

As addressed above, when an antimicrobial lubricant is used to provideantimicrobial protection to these dermal layers, there is a greater riskof toxicity because it is difficult to ensure that the antimicrobialagents will be localized to the dermal layers and not introduced intothe patient's vasculature at toxic levels. In contrast, by employing anantimicrobial coating comprising a base material that elutesantimicrobial agents, the antimicrobial agents can be accuratelydistributed to the dermal layers 302 and released at a rate thatprovides long term antimicrobial protection. In other words,antimicrobial coating 103 can limit the total amount of a particularantimicrobial agent that elutes throughout the life of the device, andconcentrate the agent in the area of maximum benefit.

To ensure proper positioning of antimicrobial coating 103 when vascularaccess device 100 is used, antimicrobial coating 103 can be configuredwith an appropriate length. For example, the depth of tissue between theouter layers of skin and the intimal layers of the vein is commonlybetween 3 mm and 6 mm. Also, it is typical for 4 mm to 6 mm of thecatheter to remain outside of the skin. Therefore, in some embodiments,the length of antimicrobial coating 103 can extend from 7 mm to 12 mmfrom the catheter adapter to ensure that the distal end of the coatingis positioned at least at, if not beyond, the intimal layers of thevein.

Of course, other lengths of antimicrobial coating may be used in otherembodiments. In short, the length of the antimicrobial coating can beselected for a particular vascular access device based at leastpartially on the typical length of the catheter that remains outside ofthe skin when the particular vascular access device is used. Forexample, many catheters include a line or other indication thatidentifies how deep the catheter should be inserted. In someembodiments, the length of antimicrobial coating 103 can be based on thelength of the catheter between the catheter adapter and this type ofindication. Similarly, the length of the antimicrobial coating may alsobe based on the distance from the outer layers of the skin and theintimal layers of a vein where the catheter will be inserted (i.e. thelength can be based on the intended location where the catheter willtypically be inserted).

The antimicrobial coating of the present invention can be particularlybeneficial on a vascular access device that is used to draw blood. It isbecoming more common to draw blood samples through vascular accessdevices that have previously been used primarily to inject fluids intothe patient's vasculature. When fluids are being injected, there is lessconcern for kinking because the pressure of the fluid tends to open anykinks that may otherwise occur in the catheter. However, when these samedevices are employed to draw blood, kinking is more likely because ofthe reduced pressures and flow rates used when drawing blood. Theantimicrobial coating of the present invention can therefore beparticularly beneficial to prevent kinks during blood draw.

FIG. 4 illustrates an alternate embodiment of the vascular access devicedepicted in FIG. 3. FIG. 4 differs from FIG. 3 in that an antimicrobiallubricant 310 has been applied to the portion of catheter 101 that doesnot include antimicrobial coating 103. Antimicrobial lubricant 310, insome embodiments, may also extend at least partially over antimicrobialcoating 103. Antimicrobial lubricant 310 can provide lubrication tocatheter 101 to assist in insertion and can also provide additionalantimicrobial protection throughout the insertion site. For example, ascatheter 101 is inserted, antimicrobial lubricant 310 can rub off on thedermal layers of the skin to provide immediate and concentratedantimicrobial protection. Then, antimicrobial coating 103, oncepositioned within the dermal layers, can continue to provideantimicrobial protection in a controlled release and targeted manner.Antimicrobial lubricant 310 can also assist in preventing clots fromforming on and in catheter 101, particularly in the distal opening oropenings of catheter 101.

FIG. 5 illustrates another alternate embodiment of the vascular accessdevice depicted in FIG. 3. FIG. 5 differs from FIG. 3 in thatantimicrobial coating 103 extends to the distal end of catheter 101. Insuch cases, an antimicrobial lubricant, although not depicted, may alsobe used.

In accordance with one or more embodiments of the invention, anantimicrobial coating can be applied to a vascular access device bydispensing an uncured base material on the catheter adjacent thecatheter adapter. This base material can be applied while spinning thecatheter slowly (e.g. between 20 and 120 rpm). The catheter can continueto be spun while a die is used to draw the base material over thedesired length of the catheter. In some embodiments, a clamshell die maybe used. Then, the coating can be cured. In some embodiments, thecatheter can continue to be spun while the coating is cured.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

1. A vascular access device comprising: a catheter adapter; a catheterthat extends distally from the catheter adapter; and an antimicrobialcoating applied to at least a portion of the catheter, the antimicrobialcoating comprising a base material that releases one or moreantimicrobial agents when the antimicrobial coating is inserted within apatient's skin, the base material providing kink resistance to thecatheter.
 2. The vascular access device of claim 1, wherein theantimicrobial coating is positioned adjacent the catheter adapter. 3.The vascular access device of claim 1, wherein the antimicrobial coatingincludes an increased diameter portion.
 4. The vascular access device ofclaim 3, wherein the increased diameter portion is positioned adjacentthe catheter adapter.
 5. The vascular access device of claim 4, whereinthe diameter of the increased diameter portion increases towards thecatheter adapter.
 6. The vascular access device of claim 1, wherein adistal end of the antimicrobial coating is positioned proximal to adistal end of the catheter.
 7. The vascular access device of claim 6,wherein the distal end of the antimicrobial coating is positioned at adistance from the catheter adapter that is based on an intended lengthof the catheter that should exist between an intimal layer of a vein andthe catheter adapter when the catheter is inserted intravenously.
 8. Thevascular access device of claim 1, wherein the length of theantimicrobial coating is between 7 mm and 12 mm.
 9. The vascular accessdevice of claim 1, wherein the base material is hydroscopic.
 10. Thevascular access device of claim 1, wherein the base material is one of aUV cured acrylate-urethane or a heat-cured polyurethane.
 11. Thevascular access device of claim 1, wherein the catheter comprises amaterial, and a hardness of the base material is greater than a hardnessof the material of the catheter.
 12. The vascular access device of claim1, wherein a thickness of the antimicrobial coating at a distal end ofthe antimicrobial coating is between 10 microns and 100 microns.
 13. Thevascular access device of claim 1, further comprising: an antimicrobiallubricant applied to the catheter.
 14. The vascular access device ofclaim 13, wherein the antimicrobial lubricant is applied to a portion ofthe catheter that does not include the antimicrobial coating.
 15. Avascular access device comprising: a catheter adapter; a catheter thatextends distally from the catheter adapter; and an antimicrobial coatingon the catheter, the antimicrobial coating extending from the catheteradapter towards a distal end of the catheter, the antimicrobial coatinghaving an increased diameter portion adjacent the catheter adapter. 16.The vascular access device of claim 15, wherein the antimicrobialcoating comprises a base material that elutes one or more antimicrobialagents when the antimicrobial coating is positioned within a patient'sskin.
 17. The vascular access device of claim 16, wherein theantimicrobial coating has a hardness in excess of a hardness of thecatheter.
 18. The vascular access device of claim 15, wherein a distalend of the antimicrobial coating is positioned at a length from thecatheter adapter that corresponds with a length of the catheter that isintended to exist between an intimal layer of a vein and the catheteradapter when the catheter is inserted into the vein.
 19. A cathetercomprising: an antimicrobial coating applied to a portion of thecatheter, the antimicrobial coating having a proximal end and a distalend, the proximal end comprising an increased diameter portion, theantimicrobial coating comprising a base material that releases one ormore antimicrobial agents when the antimicrobial coating is positionedwithin a patient's skin.
 20. The catheter of claim 19, furthercomprising: a catheter adapter from which the catheter extends, thecatheter being positioned within the catheter adapter such that theproximal end of the antimicrobial coating is positioned adjacent thecatheter adapter.